Process for the manufacture of unsaturated aldehydes



Patented :June 17, 941

PROCESS FOR THE MANUFACTURE OF UNSATURATED ALDEHYDES Milton Gallagher, Louisville, Ky., and Rudolph 7 Leonard Hasche, Kingsport, Tenn., assignors to ,Eastman Kodak Company, Rochester, N. Y., a :corporation of New Jersey No Drawing.

Application October 5, 1940, Serial No. 859,932

SClaims. (01. 260-601) Unsaturated carbonyl compounds and, in par ticular, acroleins have a number of uses. These organic compounds may be converted to other chemical products. For example, acrolein may be converted to propionic aldehyde in accordance with the methods of our U. S. Patent No.

2,150,158, or to acrylic acid, glycerine, or other compounds.

While methods of preparation wherein a single aldehyde combines with itself, are known, apparently few methods have been developed for the manufacture of the unsaturated carbonyl compounds and in particular unsaturated aldehydes. Prior to our invention the manufacture of unsaturated carbonyl compounds has been confined in a number of instances to expensive and unsatisfactory processes. In the instance of acrolein, prior to our invention, acrolein has been prepared, for example, by dehydrating glycerol.

Another method that has been suggested for producing acrolein is to make the mono-chlor substitution product from propylene, then to hydrolyze it to allyl alcohol followed by dehydrogenation to acrolein. However, this has the same objection as the dehydration of glycerol in that the over-all yield is very low.

In Monatshefte fur chemie, volumes 21 and 22, are described a number of methods for reacting two different aldehydes. However, these methods in most instances involve the use of a solution of potassium salts and produce only aldols. Furthermore, the methods indicate that several days may be required in carrying them out and that several steps may be involved.

We have found a new method for the manufacture of unsaturated carbonyl compounds, and in particular unsaturated aldehydes such as acrolein, which is superior in a number of respects to processes previously employed in the manufacture of such carbonyl compounds.

- inafter.

ess operating under diflerenttemperature and other conditions, as will be more apparent here- In our copending applications'above identified, we have described the reaction specially as carried out in the presence of a catalyst and wherein the compounds reacted comprise aldehydes. However, our invention has wider applications. While in the preferred embodiment of the invention,-the reaction chamber would preferably be filled with a solid material not only functioning to distribute the heat but also functioning in a catalytic capacity, we have found that our reaction can be caused to proceed when carried out in the reaction chamber containing a relatively inertand non catalytic material. We have further found that when operating without catalytic materials, or with only small amounts thereof that higher temperatures may be employed and preferably would be employed for maximum yields. While our preferred reaction is carried out employing a carbonyl compound such as a lower aliphatic aldehyde, our invention embraces the utilization of other carbonyl compounds having at least two hydrogen atoms on the carbon atom adjacent-the carbonyl group, as also described in greater detail hereinafter.

We have found an efilcient and highly desirable procedure wherein two different carbonyl compounds may be caused to combine to produce vinyl carbonyl compounds containing a number of carbon" atoms equal to the sum of two reactants.

It will be noted thatprior art attempts to react two different carbonyl compounds have not resulted in the production of vinyl carbonyl compounds but have either failed outright or resulted in the production of some other compound such as, for example, penta-erythritol from formaldehyde and acetaldehyde.

This invention has'for an object to provide a process for the combination of two different carbonyl compounds to produce a vinyl carbonyl compound containing a number of carbon agims equal to the sum of the two carbonyl reactants.- ,Another object is to provide a novel process for the production of unsaturated aliphatic aldehydes. Still another object is to provide a novel process for the production of unsaturated ketones.

at least two carbonyl compounds having a di iTerent number of carbon atoms in the molecule.

In accordance with our preferred procedure, we have found that highly desirableresultsmay' be' reactants or in addition to this function it might also exert a catalytic function.

In accordance with the preferred operation of our process, as described in detail in our copending application 232,160, the reaction space is filled with a material which functions as a catalyst; .for example, various gels have been described as these materials due to their absorptive characteristics, apparently. tend to aid in the splitting oflf of water and therefore may be considered as solid dehydration catalysts.

obtained by reacting formaldehyde and another carbonyl compound in accordance with' the procedure set forth herein.

In-carrying out our process various types of apparatus may be employed and ourinvention is not limited in this respect. For example, a container would be provided for one of the carbonyl compounds and a second container pro-- vided for another of .the carbonyLcompounds.

These units could be connected to separate vaporizers or a single vaporizer.

In other words. some meanswould merely be provided for convertlng the carbonyl compound to a-vapor, and the vapors could be substantially mixed .-in the event that the carbonyl compounds have not been premixed. The Vaporizers could then be able configuration. A cylindrical chamber would be satisfactory, and in accordancewith our preferred embodiment, the reaction chamber would be filled or packed with some material as will be discussed, hereinafter. The material may be non-catalytic, catalytic, or a mixture thereof'and would function to distribute thereactants and transfer the heat thereto.

Any suitable means for heating, such as electric heat, gas heat, hot. oil, or any of the numerous heat transferring compounds may be employed. Also'sultable provision may be made for heat-exchange or other similar expedients adopted. The discharge from the reactionchamher would preferably be through a condenser or other cooling means.

Inasmuch as suitable apparatus for carrying out our process is described in our companion Patent 2,150,158 and suitable vaporizing units and the like are described in detail in Hasche Patent 2,173,111, further description respecting apparatus appear to beunnecessary.

In the carrying out ofour process we have found that two different. carbonyl compounds may be readily reacted toform' an unsaturated carbonyl compound .provided the reaction is caused to take place in the vapor phase. The exact temperatures under which the reaction takes place will depend to some extent upon pressure conditions. Inasmuch. as our process functions very satisfactorily under ordinary atmospheric premures, for simplicity we generally carry our process out under these conditions and In more detail, there are a number of other catalysts'which have been employed and which function satisfactorily in our process. Among these other catalysts, the following may be mentioned: Y

The following materials were tried in an amount equal to 2.5% of the weight of the support: W0: and V205.

Five per cent of catalytic materials were used in. the following cases: Formates of Zn, Mg, Cd, Hg, Ca, Ba, Cu, Ni++, Mn++, and Co++. The following acetates were used at 5%: Zn, Mg, Cd, Hg, Ba, Ca, Cu, Ni++, Fe++, Mn++, and Sr.

Five per cent of the following propionates were examined: Mg, Cd, Ca, Co++, Ni++, Ba, Cd and connected with the-reaction chamber of any suit- The following were also used at 5%: Ca(OH)2,

Mgoxalate, Mgsof, Mg(NOa)a, MgClz, mgcroi,

KCl, omen roof, Bemom, zruwo'm, Cr nitrate, phosphotungstic acid, uranyl nitrate, phosphomolybdic acid and Th(NCa) 4.

Twenty per cent of the following was tried.

Ni(NO3)z, and NazCOs.

Fifty per cent of Mg(OAc) s was employed. From 0.45 to 2.0% of the following were tested:

' Mg(OAc)z, FezOa, ThOz, Th(NO3)4, KzCOJ, metal usually at a temperature in excess of 200 C. but

not greater than about 600 C.

It should be noted, however, thatalthough our reaction may be carriedzout under a variety of conditions, it is highly desirable that the process be conducted in a substantially continuous single step and under vapor phase conditions. 'In the preferred operation of our process, the. reaction space wherein the two difierent. carbonyl compounds are caused to react inthevapor phase, would preferably be. filled with some material which might function merely to distribute the (A8002, W03, Al(OH)a, cnorm, c1013, AlCla.

Zr(NO3) 4, KzCOa and Th(NO3) 4.

The following combinations of materials were tried as catalysts:

g( c)2+ V203 lIg(0AC): a)4 g(OAc)-z +K2C03 M wAc C(NO3)3 A number of combination catalysis of MgO were prepared with at least one of the following materials: Co, Ba(0I-I)z, F6203, H3PO4, ThOz, V205, W03. Ce(NO;)z, AgO, Cd, Ag, Cu, Co.

The aforementioned catalysts were prepared by the following methods:

' A. To g. of silica gel was added an aq. acid solution prepared by adding 15 cc. of strong acetic acid to 35 cc. of water, followed by gentle warming and the addition of 10 g. of ZnO, MgO, NiCOs, CdO or any other basic oxide or carbonate or hydroxide of the desired metal. Any excess liquid was removed by heating either with or without reduced pressure.

B. To 100 cc. of silica gel treated as above was added 10 g. H2304 diluted to 30 cc. with water. By this procedure the above acetates were completelyconverted to the corresponding sulfates generically as combination catalysts comprising supports: such tions -tlrereof mi-ght be substituted wholly or in precipitated directly on or within the" poresrofil the gel. 1

C. To 100 cc. of silicaigel was added-" g."

H2804 to which had been added cc. H2O? To this gel so treated was added the aq. acid solution.

part fortliecatalytic' material employed in this example; '1'I'l'ief filling" material in the reaction of the metal salt as preparedin (A). This-sc t complished essentially the same results'aswB) but produced a more active catalyst."

D. Similar procedures were followed iii-prepar ing chromates, phosphates; molybdatea etc.

- The other catalysts described above. maywbei prepared by the samegeneral steps*A', B, C

already' set forth, It is to be understood-it-hat while in the process examples sulphuric acid -and 1 other such specificagents havebeen describedj other inorganic and organic acidsor chemicalsmay be employed. For example, in place-.ofitlie sulphuric acid, phosphoriccould be employed. While in the above examples in many instances the impregnating or mixing metal or metal salts was employed in amounts from .45% m5 or10%', I it will be observed that amounts as high as 50%- were employed. Therefore, while weprefer" a base impregnated or mixed with a minorproportion of'a metal or metal salt, we donot wishto' be restricted to these embodimentstinasmuch as the proportions may be varied. We have. also found that the silica gel and alumina/gel may" be mixed in varying proportions.

For convenience, we designate our "catalystsdehydrating catalysts." The as gels, charcoal, magnesia, or the like, impreg w v nated or mixed with the various metals andmetat salts specified, we sub-generically desi'gnated'iasimpregnated or mixed dehydratingcatalysta However, while the foregoing representswthe preferred filling or packing material forthe reaction space, as will be pointedout in more detail hereinafter, the reaction space may be'filledwith" some relatively inert non-catalytic material'such'. as sea sand or metal gauze, or pelleted'materials, or the tube might be filled with brick; porcelain, or other means for deflectingthe...reactanta1 gases against the sides of the.reaction spaceifor. I better heat absorption. In the'event thatinert materials are used, or a narrow, unfilled reaction space employed, higher temperatures wouldrbe' applied to the reactionspace'than, forexample,

where an active catalytic filling material "was" present in the reaction space.-

From the foregoingit is'also readily-apparent that various combinations of materials 'can-abe" spacewas electrically heatedby means of a coil I surrounding? theireaction chamber.

During a run" of about six hours, approximately 101.3:giamsof formalin containingapproximately 35% formaldehyde byweight, were fed to the reaction "space: Theifilling materials in the reaction space; inthis example, were held at approximately"285 "C. After a' period of' operation,

which maywbe-"fromyior example; twelve to twenty-four: hours, the filling material may be removed"and fresh material-introdubed, or the 15;

removed material 'mayabe regenerated .or, otherwise renovatedz'an'dreturned;

'Il1e'-reaction-product in this example contained a substantial amount of acrolein "which was drawn offends-the acrolein maybe hydrogenated, 20

' of "further treating the acrolein' being described oxidized,'polymerized,.or otherwise treated, a step in greater detail in our Patent 2,150;l58. Forconvenience ofreference, other'exampl'es of operatingour: process are set-forth'below intabular' form; It is tobeunderstood'thatlin these examples similar:procedure to that outlined above is followedrexcept that in the'runs described in th'e' table ia rel'atlvel'y inert non-catalytic material was-placed 'in-cthe reactionspace-and the two different carbonyl 'compoundsreacted in the presence-of this heated inert-material.-

' i Catalyst data and/or filling Temg Run m- Penman-$5 material No." turen onto heir g? I 8 Support; Fillingea'; v I v I l06. .300 0/451' 11140 .Monazite sand None. 24..-. 266 0.66 750 :Argtvated car- Do. n. Y 26*" -297 5 t 750 'Activiated char 5% NAQCOS. coa 6 745; 320 "(124* 1,200' .Sea sand; None.,

I Theabove'describedzreactions are merely'illustrativatandit is to be'understood that in place of the catalyst and/or'fillingmaterials described, various .btherr'substances might be substituted, as for example; broken brick; porcelain, metal gauze, pelleted materia'l: andrthetlike: Also, the reactions' have been "illustrated by: the employment of the ..carbonyl*.compounds;" formaldehyde; and

-. acetaldel'rydezqas -thesecompoundsrepresent'oer-' employed. For example, inert materialarsuch as sea sand or other non-catalytic materials, maybe coated or mixed with catalytic materiaisand employed in the reaction space asfilling.

The carrying out of our new process"will be" more apparent from the followinggenerirlgexampie which is set forth for the purposeof'bro'ad ly illustrating our process: i

In carrying out this example the carbonyl compound to be reacted was an aldehyders: Q'ne container was filled with relatively pure: liquid:

acetaldehyde. Another container was fillediiwitli" The two materials were allowed; to" flow to a mixing point and then into a vaporizer formalin.

or flash unit. The mixture of acetaldehyde and formalin was vaporized and the vapors conducted to a packed reaction space; as referred to'above-s In the particular instance under: consideratibmnthe reaction space wasfilled with :*a.'catalytic material. However, it is to be understoodaour invention is not exactly limited in this:respect because any of the filling materials. orcombina tain: iof theelowermost "members :of the groups .-of our 1 reactantswI-Iowever; as will be described in greater -detail hereinafter: various other carbonyl compounds' mawbe" substituted I in the foregoing reaction; 1

In, our processi it: is possible to use carbonyl compounds from various sources." 1 For example, the iacetaldehyde maysbe-* obtained synthetically from acetylene; The: acetylene may I be'fproduced from calcium carbide; cracking hydrocarbons or theidecomposition"ofihydrocarbons in an electric arc; .'Iiie 1i acetaldehyde may also be obtained from ethyl i alcohblii It will' thusvbe:apparent ithat' the 'purityi'of the acetaldehyde is not important? Relatively-purerformaldehyde boils" at approximatelyi- 2l 0. .Formalin, which". contains around idiw of formaldehyde; the remainder belng principally methyl .r alcohol and water, is an easier source .otsformaldehydeto work' with. Also formalin...isi'readilyiavailable: commercially. We have :found that the methylalcohol. content of formalin or: other isources of formaldehyde does The vapors from the reaction chamber are usually passed through a cooling device. The desired unsaturated carbonyl compound, containing water, any .unreacted formaldehyde. and saturated carbonyl compound maybe withdrawn. The unreacted components mayv be separated and recirculated if desired.

The unsaturated carbonyl compoundmay be recovered as such and employed or, the com-- pound may be converted to different chemical compounds by hydrogenation, oxidation, polymerization, or other treatment. Excellent yields of acrolein were obtained. v

In place of the acetaldehyde orv other higher aldehyde described in the foregoing illustrative examples, other carbonyl compounds may be substituted. Illustrative thereof are the lower aliphatic ketones of the series commencing with acetone, methyl-ethyl ketone, diethyl ketone, and the like. The specific reactionof such ketones forms the subject matter of copending application of Brant and Hasche 280,808, filed June 23, 1939.

Our reaction, which has been specifically illustrated as respects the utilization of aldehydes,

may be generically illustrated as follows:

wherein El and Rs represent hydrogen, alLvl, aryl, or heterocyclic. For example, when R1 is an alkyl group the carbonyl compound then would be a ketone. When R1 is hydrogen, the carbonyl compoimd is an aldehyde. It will be observed that our carbonyl compounds are characterized in that the carbon atom adjacent the carbonyl group will contain at least two hydrogen atoms. We have found that in such a configuration that the two hydrogen atoms on the adjacent carbon atom are apparently activated to some extent by the carbonyl group when the reaction is in the vapor phase, and therefore readily com-' blue, for example with formaldehyde.

We also contemplate that the unsaturated compounds in the reaction product from our aldehyde reaction may be further treated and/or copolymerized or otherwise reacted with the various reaction products obtained from our. reaction resulting from, the use of a carbonyl compound other than aldehydes, as ketones." r

The above examples are merely illustrationsof conditions for carrying out our processes. The reaction conditions may be varied and the above examples are not to be construed as limiting our invention. For example, the mole ratio of the second carbonyl tothe first carbonyl (as acetalsmaller than the yield based on the other carbonyl compound and we have found that a more complete utilization of the formaldehyde could be obtained by using the higher ratio.

The space velocities for the formation of the unsaturated compounds may vary according to conditions and reaction equipment. We have found a range from 200-3000 to be suitable for carrying out our reaction. We may define space velocity" as cubic feet of reactants fed per cubic foot of filled or packed reaction space per hourvolumesof reactant materials measured at temperatures and-pressures of reaction. As already indicated, the temperature range may generally vary from about 200' C. to 400 C. However, in the absence of any catalyst higher temperatures up to 600 C. may be employed. While we prefer to carry out the reaction under atmospheric conditions, it is possible to carry out the reaction under either higher or lower pressures.

Our novel procedure described herein represents a particularly satisfactory method for the manufacture of unsaturated carbonyl compounds. Our preferred embodiment for the manufacture of acrolein and vinyl ketones permits the utilization of materials, such as formalin, and other common materials.

While our process is particularly adapted for the preparation of the unsaturated aliphatic aldehyde acrolein as described in the tables, our invention has wider applications and embraces similar procedure for the formation of other mixed products. An example of the formation of an unsaturated aldehyde with an even number of carbon atoms is the reaction between formaldehyde and proplonaldehyde to form a methacrylic-aldehyde.

Our process does not require the utilization of high pressures because the reaction is not accompanied by an increase or decrease in volume. Our process is also particularly desirable from the standpoint that any by-products produced are few in number and in relatively small quantities when our process is properly employed. Any unreacted components may be re-utilized by circulation through the system.

It will be understood that our apparatus will be constructed of suitable materials and that proper precautions for preventing heat losses and leakage will be observed. We find that many of the parts of our apparatus may be constructed of a steel containing about 16-23% chromium, about '7%-20% nickel and the balance substantially iron. This steel preferably has a content of carbon of about 1 6% or less. The steel may also contain small amounts of molybdenum, columbium, copper, silicon. and tungsten.

It is,therefore. apparent that while we have described our invention in some detail, there are many changes that may be made therein without departing from the spirit of the invention.

. What we claim is:

,1. A process for producing unsaturated aliphatic carbonyl compounds which comprises passing mixed vapors containing formaldehyde and another lower aliphatic carbonyl compound containing only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adJacent the carbonyl group, into condehyde to formaldehyde), while generally kept tact with a mixture of relatively inert non-catslytic filling material with a condensation catalyst, at a temperature, at least part of the time, at which the reaction will take place under vapor phase conditions and water is split ofi, whereby an unsaturated aliphatic carbonyl compound is formed.

2. A process for producing unsaturated aliphatic carbonyl compounds which comprises passing mixed vapors containing formaldehyde and another lower aliphatic carbonyl compound containing only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group, into narrow spaces, at a temperature at least part of the time. at which the reaction will take place under vapor phase conditions and water is split oil. whereby an unsaturated aliphatic carbonyl compound is formed.

3. A process for producing unsaturated aliphatic carbonyl compounds which comprises passing mixed vapors containing formaldehyde and another lower aliphatic carbonyl compound containin only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group into con tact with relativelyinert non-catalytic filling material, at a temperature, at least part of the time, at which the reaction will take place under vapor phase conditions and water is split off, whereby'an unsaturated aliphatic carbonyl compound is formed.

4. A process for producing unsaturated aliphatic carbonyl compounds which comprises passing mixed vapors containing formaldehyde and an excess of another lower aliphatic carbonyl compound containing only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group into narrow spaces at a temperature greater than 200 C., at least part of .the time, whereby the reaction will take place under vapor phase conditions and water is split off, thereby forming an unsaturated aliphatic carbonyl com pound.

5. A process for producing unsaturated aliphatic carbonyl compounds which comprises passing mixed vapors containing formaldehyde and an excess of another lower aliphatic carbonyl compound containing only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group into contact with relatively inert non-catalytic filling material at a temperature greater than 200 C., at least part of the time, whereby the reaction will take place under vapor phase conditions and water is split ofi', thereby forming an unsaturated aliphatic carbonyl compound.

6. A process for'producing unsaturated aliphatic carbonyl compounds which comprises heating mixed vapors containing formaldehyde and an excess of another lower aliphatic carbonyl compound containing only one oxygen atom and-no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group in contact with relatively inert non-catalytic heat distributing material at a temperature greater than 250 C., at least part of the time, whereby the reaction will take place under vapor phase conditions and water is split off, thereby forming said unsaturated carbonyl compound.

7. A substantially single step process for pro ducing unsaturated aliphatic carbonyl compounds which comprises heating mixed vapors containing formaldehyde and another lower aliphatic carbonyl compound containing only one oxygen atom and no other elements than carbon and hydrogen and having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group, in packed narrow spaces at a temperature above 200 (3., at least part of the time, whereby the reaction will take place under vapor phase conditions and water is split off, thereby forming an unsaturated aliphatic carbonyl compound.

8. A substantially continuous single step process for' producing vinyl carbonyl compounds which comprises heating mixed vapors containing formaldehyde and another lower aliphatic aldehyde having at least two hydrogen atoms attached to the carbon atom adjacent the carbonyl group in contact withrelatively inert noncatalytic heat distributing material at a temperature above 200 C. at least part of the time whereby the .reaction will take place under vapor phase conditions and water is split oif thereby forming a vinyl carbonyl compound.

MILTON GALLAGHER.

RUDOLPH LEONARD HASCHE. 

